Races Half marathon · Portsmouth, USA
Seacoast Half Marathon
Seacoast Half Marathon is a rolling half marathon in Portsmouth, USA, held each October. A loop from Portsmouth High School through Portsmouth, rural Rye and New Castle, with coastal views. The organiser calls it mostly flat with rolling hills, between 2 m and 20 m above sea level. Late October on the New Hampshire coast is typically cool and crisp, with temperatures of about 3 to 14°C. The rises around Portsmouth are small but relentless — train on similar terrain and race by effort, not pace.
Page rebuilt 2026-11-14 · race facts not independently verified — confirm dates and entries on the official race site
When
October
every year
Course
rolling
Half marathon
Conditions
Late October on the New Hampshire coast is typically cool and crisp, with temperatures of about 3 to 14°C.
Racing this course well
A loop from Portsmouth High School through Portsmouth, rural Rye and New Castle, with coastal views. The organiser calls it mostly flat with rolling hills, between 2 m and 20 m above sea level.
The rises around Portsmouth are small but relentless — train on similar terrain and race by effort, not pace.
Getting a place
Official Seacoast Half Marathon site →Checked November 2026
Race day
- Start time
- 08:30
- Pacers
- Seven pacers from 7:00 to 10:00 minutes per mile, at 30-second steps
The course in numbers
The route runs out through Portsmouth and Rye, returns to the Foye's Corner traffic circle, then crosses to New Castle before the run back to the school. Split clocks stand at 1, 5 and 10 miles.
- Layout
- Loop
- Surface
- Local and town roads
- Total climb
- 115 m (380 ft)
- Men's course record
- 1:08:02 (Teage O'Connor, 2018)
- Women's course record
- 1:17:19 (Andrea Walkonen, 2012)
- Course status
- USATF-NE certified
Worth knowing
- First run in 2006.
- The first race in 2006 raised funds for the restoration of the Market Square steeple in Portsmouth.
- The race is run by volunteers, and the net proceeds go to a different local charity each year.
- Walkers start at 8:00, half an hour before the runners.
Pick your goal for Portsmouth
Pace charts, weekly structure and timelines for the most common half marathon goals:
We don’t hold a confirmed date for this edition, so any countdown comes from the date you enter here.
Build your training around Seacoast Half Marathon.
RunV works backwards from race day to today. Your plan adapts when life interrupts, and you approve every change. It does not adapt to this specific course — the pacing guidance above is where the course knowledge is.
Everything above stays free and complete — this is an optional next step, not a paywall.
Asked often
- When is the Seacoast Half Marathon?
- It is held each October in Portsmouth, USA. Check the official Seacoast Half Marathon site for the exact date and entry windows.
- Is the Seacoast Half Marathon course flat?
- A loop from Portsmouth High School through Portsmouth, rural Rye and New Castle, with coastal views. The organiser calls it mostly flat with rolling hills, between 2 m and 20 m above sea level.
- How should I train for the Seacoast Half Marathon?
- Build for the course you'll actually race at the Seacoast Half Marathon: rolling terrain, October conditions. RunV Premium builds a training plan around your goal time and race date, and lets you adapt it when life interrupts the Portsmouth build.
Not sure what to target? Predict your half marathon time from a recent race →
More half marathon races
Supplements research for this distance
Build for Portsmouth — around your actual life
RunV engineers your block backwards from race day in October — and adapts it when training doesn't go to script. You approve every change.
